A radio wave includes frequencies which become noise in addition to effective frequencies. Accordingly, when use conditions and an emission situation of radio waves is analyzed, whether a received radio wave is a frequency of an analysis target or a frequency of noise or not needs to be distinguished.
For example, in patent literature 1, there is disclosed a method to carry out processing to: detect, by comparing a standard DISPLAY line (a standard power level) set by an observer in advance and a broadband frequency spectrum signal outputted from a frequency domain equalization unit, a radio wave having reception power higher than the standard DISPLAY line; and calculate the features of the radio wave.